rbowall is partly correct. 32 bit OSs can only address 4 GB of RAM. But windows gives each application 4 GB of RAM address space even though most will never come close to using it. The pagefile is used to store things that are in RAM but not used much. One of my servers has 2.25 GB of RAM and a 3.5GB page file. And the total available RAM (as reported by Task Manager under "Commit Charge (K) in the performance tab is roughly 5.75 GB (5800816).